1. Field of the Invention
This invention relates to tube couplings.
2. Background Prior Art
More particularly, the invention is concerned with tube couplings comprising a coupling body having a throughway open at one end to receive an end part of the tube, sealing means in the throughway to form a sealing engagement with the end part of the tube located in the throughway, and a locking device engageable with an annular bead on the tube adjacent to said end part to hold the end of the tube in the coupling body in engagement with said sealing means. A problem which can arise with such an arrangement is that a tube can be pushed into the coupling body and the resistance offered to entry of the tube by the seal may appear to indicate to the operator that the tube has been locked in the coupling body but this may not be so and the bead on the tube may not have engaged the locking device. Thus, when pressure is applied to the coupling, the tube may be simply blown out of the coupling resulting in loss of fluid and potential danger where the fluid is either flammable or corrosive.